72 W. ARCHER. 



practicable to do for the Heliozoa what Hackel has done for 

 the Eadiolaria and Carpenter for the Foraniinifera. 



Previous to entering upon the recently described accessions 

 to the Monothalamatons Sarcodina, appertaining to the 

 fresh water, two very distinct forms found in sea-Avater, 

 having Actinophryan resemblances, to say the least, claim a 

 brief notice. 



Actinolophus pedunculatus, 

 Eilh. Schulzei (Plate XXII, figs. 26, 27, vol. xvi, 1876). 



Though marine in habitat the form named above seems to 

 claim a notice in the present resume. Seated on various 

 hydroid Polypes, and even on sea-weeds, the author found 

 at various times of the year, but mostly in summer, this 

 remarkable stipitate animal form, in outer habit resembling 

 a Podophrya occurring in its company, but in no way belong- 

 ing to the Acinetae, but truly appertaining to the Rhizo- 

 poda. 



The stipes is cylmdrical (length, 0-06 c. OT mm., breadth, 

 0-003 — 0-004 mm., figs. 26, 27) ; without any basal plate 

 or expansion of any kind; its lower end stands directly upon 

 the substratum, whilst at the upper end it bears the body. 

 It is perfectly colourless and hyaline. The author concludes 

 from the outer layer appearing doubly contoured that it 

 consists of a delicate tubular sheath of chitinous nature, 

 enclosing slight refractive contents. In the interior a few, 

 usually three, mutually equidistant parallel fine lines can 

 be seen mostly running longitudinally through its whole 

 length ; but in some cases confined to the upper portion of 

 the stipes only (figs. 26, 27). 



The body borne at the apex of the stipes is usually pyri- 

 forpi, its narrower end downwards (fig. 26), but the by no 

 means inconsiderable contractility of its mass enables it to 

 assume various figures, from ovate to globular. A^^art from 

 the pseudopodia it is always smooth and of a simple contour 

 (length, 0-02— 0-03 mm.; breadth, 0-015 mm.). The 

 hyaline plastic {" zahfllissig ") basic substance (as is usual in 

 Sarcodina)shows numerous fine and coarse more or less re- 

 fractive granules embedded therein. The author could not 

 perceive any special membrane nor any ectosarc. In the 

 interior occurs constantly a nucleus, which strikes the eye 

 as much by its extremely large nucleolus as by its excentric 

 position (fig. 26). The oval rarely globular, homogeneous, 

 and rather strongly refractive smoothly-contoured nucleolus 

 has a diameter of about OOOo — 0-004 mm., and shows around 



' Scliiilzp, ' ScliuKzc's Archiv,' Bd. X, p. 392, t. xxvii, IT. 1—9. 



